In April I came across this rhizotomous sedge in a low terrace of the East Branch Chagrin River in Northeast Ohio. I had a difficult time keying it out but after narrowing it down I concluded that it was Carex woodii. "Carex woodii is a plant of rich, often moist, deciduous forest, especially beech-maple, an early species fruiting mid-May or earlier" Voss and Reznicek, Field Manual of Michigan Flora. The timing and location of my find seem to fit well with the description - this is a rich beech-maple forest and it was early in the season.
My best attempt with a camera phone to capture the colony of what I think is Carex woodii.
A single clump plucked to show the shallow dark rhizome.
Some sketches I made to show some of the features of this Carex.